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cable distribution amplifiers

 

 

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ajlill at ajlc

Mar 7, 2004, 5:46 PM

Post #1 of 8 (1033 views)
Permalink
cable distribution amplifiers

Since I've added my mythtv box with it's 2 capture cards, my cable
signal has been a bit weak (go figure)! Has anyone tried a cable amp,
and do they work well?
--
Tony Lill, Tony.Lill[at]AJLC.Waterloo.ON.CA
President, A. J. Lill Consultants fax/data (519) 650 3571
539 Grand Valley Dr., Cambridge, Ont. N3H 2S2 (519) 241 2461
--------------- http://www.ajlc.waterloo.on.ca/ ----------------
"Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"


jishywa at wi

Mar 7, 2004, 6:03 PM

Post #2 of 8 (1029 views)
Permalink
RE: cable distribution amplifiers [In reply to]

We sell them at radioshack, and 75% of the time they come back the next day.
I'd stay away from them if possible. A better option is to reduce cable runs
where possible and look for worn through insulation and shielding as well as
rust on the ends. A good high quality cable helps too; get some of that quad
shielded stuff for the longest runs in your house if you feel like
replacing.

If you must go with a cable amp, put it as close to the cable entry point in
your house as possible. Otherwise you run into Garbage in -> Garbage out.

Good luck

-----Original Message-----
From: mythtv-users-bounces[at]mythtv.org
[mailto:mythtv-users-bounces[at]mythtv.org] On Behalf Of Tony Lill
Sent: Sunday, March 07, 2004 6:46 PM
To: mythtv-users[at]mythtv.org
Subject: [mythtv-users] cable distribution amplifiers

Since I've added my mythtv box with it's 2 capture cards, my cable
signal has been a bit weak (go figure)! Has anyone tried a cable amp,
and do they work well?
--
Tony Lill, Tony.Lill[at]AJLC.Waterloo.ON.CA
President, A. J. Lill Consultants fax/data (519) 650 3571
539 Grand Valley Dr., Cambridge, Ont. N3H 2S2 (519) 241 2461
--------------- http://www.ajlc.waterloo.on.ca/ ----------------
"Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"


mythtv at lakedaemon

Mar 7, 2004, 6:46 PM

Post #3 of 8 (1004 views)
Permalink
Re: cable distribution amplifiers [In reply to]

Josh (jishywa[at]wi.rr.com) scribbled:
> We sell them at radioshack, and 75% of the time they come back the next day.
> I'd stay away from them if possible. A better option is to reduce cable runs
> where possible and look for worn through insulation and shielding as well as
> rust on the ends. A good high quality cable helps too; get some of that quad
> shielded stuff for the longest runs in your house if you feel like
> replacing.
>
> If you must go with a cable amp, put it as close to the cable entry point in
> your house as possible. Otherwise you run into Garbage in -> Garbage out.
>
> Good luck
>
> -----Original Message-----
> From: mythtv-users-bounces[at]mythtv.org
> [mailto:mythtv-users-bounces[at]mythtv.org] On Behalf Of Tony Lill
> Sent: Sunday, March 07, 2004 6:46 PM
> To: mythtv-users[at]mythtv.org
> Subject: [mythtv-users] cable distribution amplifiers
>
> Since I've added my mythtv box with it's 2 capture cards, my cable
> signal has been a bit weak (go figure)! Has anyone tried a cable amp,
> and do they work well?

I'm not sure if you guys have DSL, cable-modems, or both in the great
white north. If you happen to have a cable modem, make sure it is _not_
included in the amplified string. Otherwise upstream data will be
attenuated by the amplifier, resulting in no connection.

I do remember about 15 or so years ago, cable was new and the signals
were not strong. Back then, they made a big deal out of splicing your
own cable to multiple rooms. In those days an amp helped, these days
the signal is plenty strong enough (cable co gave up? :)

Before you go rewiring your house (unless you see worn spots in the
cable), go through and replace the connectors, then make sure they are
securely plugged in to the devices (TVs, tuner cards, modem, etc). I've
found most times that a bad signal (weak) is due to insufficient
shielding. Which occurs a lot when cable installers do a half ass job
putting the connectors on the lines. Make sure to get the ones behind
the wall plates as well. Especially if they run near power cables.

HTH,

Cooper.


stanb at panix

Mar 7, 2004, 8:13 PM

Post #4 of 8 (1020 views)
Permalink
Re: cable distribution amplifiers [In reply to]

On Sun, Mar 07, 2004 at 07:46:26PM -0500, Tony Lill wrote:
> Since I've added my mythtv box with it's 2 capture cards, my cable
> signal has been a bit weak (go figure)! Has anyone tried a cable amp,
> and do they work well?

I've got a Radio Shack one in the atic, and it seems to work great. Be
certain that if your internet coonection is cable, to get a "biderctional" one.
It's not like it amplifies the upstream signal, it just does not bloack it
like osme other styles do.

--
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
-- Benjamin Franklin


james at mauibay

Mar 8, 2004, 12:47 AM

Post #5 of 8 (1011 views)
Permalink
Re: cable distribution amplifiers [In reply to]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sunday 07 March 2004 3:03 pm, Josh wrote:
> We sell them at radioshack, and 75% of the time they come back the next
> day. I'd stay away from them if possible. A better option is to reduce
> cable runs where possible and look for worn through insulation and
> shielding as well as rust on the ends. A good high quality cable helps too;
> get some of that quad shielded stuff for the longest runs in your house if
> you feel like replacing.

In general, I disagree. I won't comment on the quality of any Radio Shack
products, but the purpose of a distribution amplifier is to provide multiple
outputs at unity gain from a single input. In other words, it's an active
component that greatly reduces signal loss compared to a passive splitter.

Signal loss due to poor quality cable or long cable lengths can be significant
too, but loss due to passive splitting is very often the major issue to
overcome when feeding several devices from a single cable. A distribution
amplifier can often be the only solution.

That said, quality of the components is everything. Cheap passive 4-way
splitters can be your worse enemy, and poor quality distribution amps can be
hardly better. I've seen good quality passive splitters outperform bad amps.
High quality cables are a must, regardless of how you split the signal.

> If you must go with a cable amp, put it as close to the cable entry point
> in your house as possible. Otherwise you run into Garbage in -> Garbage
> out.

True to a point. This has nothing to do with distribution amps though. It
applies to gain amplifiers. Distribution amps do not amplify the signal above
the level of the input, they simply apply enough gain to the outputs so that
they are the same signal level as the input. Gain amps usually provide a
single output amplified up to 10 or 20 db.

Use a gain amp at your entry point to pump up your signal level to overcome
loss in your house cabling. Use a distribution amp at your entertainment
center to overcome loss caused by splitting your signal to multiple devices.

FWIW, Radio Shack used to sell a distribution amp for about $50, which the
discontinued a few years ago. For a few years they didn't have any
distribution amp product, only gain amplifiers. Sometime in the past year
they began selling a new distribution amp for about $75. It provides 4
outputs. It is part number 15-1169, and does not appear in their catalog on
their website.

BTW, I don't have any affiliation with Radio Shack at all, other than buying
the odd part from them now and again.

> Good luck
>
> -----Original Message-----
> From: mythtv-users-bounces[at]mythtv.org
> [mailto:mythtv-users-bounces[at]mythtv.org] On Behalf Of Tony Lill
> Sent: Sunday, March 07, 2004 6:46 PM
> To: mythtv-users[at]mythtv.org
> Subject: [mythtv-users] cable distribution amplifiers
>
> Since I've added my mythtv box with it's 2 capture cards, my cable
> signal has been a bit weak (go figure)! Has anyone tried a cable amp,
> and do they work well?
> --
> Tony Lill, Tony.Lill[at]AJLC.Waterloo.ON.CA
> President, A. J. Lill Consultants fax/data (519) 650 3571
> 539 Grand Valley Dr., Cambridge, Ont. N3H 2S2 (519) 241 2461
> --------------- http://www.ajlc.waterloo.on.ca/ ----------------
> "Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"
>
>
>
> !DSPAM:404be19d228751964012570!
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http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users


schepens at shaw

Mar 8, 2004, 12:55 AM

Post #6 of 8 (1010 views)
Permalink
Re: cable distribution amplifiers [In reply to]

I agree with the advice below, but despite that, a cable amp was the
right solution for me. I think the success you have with an amp depends
on why the signal's bad in the first place. If there's bad cabling or a
high degree of noise injected somewhere, the amp will just amplify the
noise along with the signal and you won't really help things. In that
case you have to replace bad cable, reduce cable length, or move cable
to decrease signal loss and induced noise, or else nag your cable
company to come out and ensure your signal strength is up to snuff.

My case was a bit different. I needed an amplifier to replace a bunch
of splitters. I had two coax splitters behind my entertainment centre.
One was a three-way, which fed the other, a two-way. I was connecting a
TV, my capture card, my digital cable box and my VCR. By the time the
signal power got split that many directions, through two splits, with
your typical low-quality non-powered, ungrounded splitters, there was
not much left of the signal. But once I put the amplifier in, the
signal was much cleaner and my hookups were far simpler. I had the
incoming cable and four outs from the amp, and that was all there was to
it. My signal quality is far better now, which is important because
I've found that the TV capture process seems to exacerbate the badness
of a bad signal.

My amp's a powered Recotron 4-output 10 dB uhf/vhf/fm amplifier, for the
record.

Jason Cooper wrote:

>Josh (jishywa[at]wi.rr.com) scribbled:
>
>
>>We sell them at radioshack, and 75% of the time they come back the next day.
>>I'd stay away from them if possible. A better option is to reduce cable runs
>>where possible and look for worn through insulation and shielding as well as
>>rust on the ends. A good high quality cable helps too; get some of that quad
>>shielded stuff for the longest runs in your house if you feel like
>>replacing.
>>
>>If you must go with a cable amp, put it as close to the cable entry point in
>>your house as possible. Otherwise you run into Garbage in -> Garbage out.
>>
>>Good luck
>>
>>-----Original Message-----
>>From: mythtv-users-bounces[at]mythtv.org
>>[mailto:mythtv-users-bounces[at]mythtv.org] On Behalf Of Tony Lill
>>Sent: Sunday, March 07, 2004 6:46 PM
>>To: mythtv-users[at]mythtv.org
>>Subject: [mythtv-users] cable distribution amplifiers
>>
>>Since I've added my mythtv box with it's 2 capture cards, my cable
>>signal has been a bit weak (go figure)! Has anyone tried a cable amp,
>>and do they work well?
>>
>>
>
>I'm not sure if you guys have DSL, cable-modems, or both in the great
>white north. If you happen to have a cable modem, make sure it is _not_
>included in the amplified string. Otherwise upstream data will be
>attenuated by the amplifier, resulting in no connection.
>
>I do remember about 15 or so years ago, cable was new and the signals
>were not strong. Back then, they made a big deal out of splicing your
>own cable to multiple rooms. In those days an amp helped, these days
>the signal is plenty strong enough (cable co gave up? :)
>
>Before you go rewiring your house (unless you see worn spots in the
>cable), go through and replace the connectors, then make sure they are
>securely plugged in to the devices (TVs, tuner cards, modem, etc). I've
>found most times that a bad signal (weak) is due to insufficient
>shielding. Which occurs a lot when cable installers do a half ass job
>putting the connectors on the lines. Make sure to get the ones behind
>the wall plates as well. Especially if they run near power cables.
>
>HTH,
>
>Cooper.
>
>
>------------------------------------------------------------------------
>
>_______________________________________________
>mythtv-users mailing list
>mythtv-users[at]mythtv.org
>http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
>

_______________________________________________
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mythtv-users[at]mythtv.org
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users


mythjoe at joebyrne

Mar 8, 2004, 11:53 PM

Post #7 of 8 (1015 views)
Permalink
Re: cable distribution amplifiers [In reply to]

I use an RCA 1->4 splitter/amp that I got at Home Despot. I run cable from
an antenna (in attic where there's no power) through a splitter (in crawl
space where there's no power) and then through the amp. The amp sits next
to my Myth box and TV. It was worth the investment. The output runs a bit
hot, though. Colors are super saturated on some channels and I get sparkles
on others. Nonetheless, I'm happy I have it.

----- Original Message -----
From: "Tony Lill" <ajlill[at]ajlc.waterloo.on.ca>
To: <mythtv-users[at]mythtv.org>
Sent: Sunday, March 07, 2004 4:46 PM
Subject: [mythtv-users] cable distribution amplifiers


> Since I've added my mythtv box with it's 2 capture cards, my cable
> signal has been a bit weak (go figure)! Has anyone tried a cable amp,
> and do they work well?
> --
> Tony Lill, Tony.Lill[at]AJLC.Waterloo.ON.CA
> President, A. J. Lill Consultants fax/data (519) 650 3571
> 539 Grand Valley Dr., Cambridge, Ont. N3H 2S2 (519) 241 2461
> --------------- http://www.ajlc.waterloo.on.ca/ ----------------
> "Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"
>
>

_______________________________________________
mythtv-users mailing list
mythtv-users[at]mythtv.org
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users


mythtv_user at lambdaaccess

Mar 11, 2004, 9:14 PM

Post #8 of 8 (1011 views)
Permalink
Re: cable distribution amplifiers [In reply to]

I have used the cheap radio shack/home depot variety cable amplifiers
as well as some very high end professional amplifiers.
Results:
radio shack/home depot ones hurt more than they help.
On the other hand I have seen amazing results from the pro-grade
stuff. There is a reason the price difference is in the $100's. This
is where I purchased the professional variety:
http://www.markertek.com/MTStore/Store.cfm?Search=rf+amplifier
I also highly recommend an adjustable gain variety.

Even the cheap $90 channelvision amp from markertek has 3dB of noise
and 15dB of gain compared with 7.5-9.8 dB noise to 10 dB of gain of the
radio shack

> I use an RCA 1->4 splitter/amp that I got at Home Despot. I run
cable from
> an antenna (in attic where there's no power) through a splitter (in
crawl
> space where there's no power) and then through the amp. The amp sits
next
> to my Myth box and TV. It was worth the investment. The output runs
a bit
> hot, though. Colors are super saturated on some channels and I get
sparkles
> on others. Nonetheless, I'm happy I have it.
>
> ----- Original Message -----
> From: "Tony Lill" <ajlill[at]ajlc.waterloo.on.ca>
> To: <mythtv-users[at]mythtv.org>
> Sent: Sunday, March 07, 2004 4:46 PM
> Subject: [mythtv-users] cable distribution amplifiers
>
>
> > Since I've added my mythtv box with it's 2 capture cards, my cable
> > signal has been a bit weak (go figure)! Has anyone tried a cable
amp,
> > and do they work well?
> > --
> > Tony Lill, Tony.Lill[at]AJLC.Waterloo.ON.CA
> > President, A. J. Lill Consultants fax/data (519) 650 3571
> > 539 Grand Valley Dr., Cambridge, Ont. N3H 2S2 (519) 241 2461
> > --------------- http://www.ajlc.waterloo.on.ca/ ----------------
> > "Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"
> >
> >
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users[at]mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
>


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